Strategy on Invasive Alien Species
Published May 2007
CONTENTS
Foreword...2
Chapter 1: Introduction ...3
Chapter 2: Background ...6
Chapter 3: Definitions...7
Chapter 4: Threats, causes and impacts...8
General background...8
Social and economic impacts...10
Agriculture ...12
Fisheries, aquaculture and imports and other movements of live aquatic organisms...15
Shipping, including ballast water...18
Hydropower developments and management of river systems ...19
Transport...20
The defence sector ...22
Travel and tourism ...22
Health ...23
Svalbard ...24
Chapter 5: International agreements and commitments ...26
Chapter 6: Norwegian legislation...30
Chapter 7: Goals and principles...34
Goals ...34
Basic principles...34
Guidelines relating specifically to alien species ...36
Chapter 8: Programme of measures ...38
Joint measures ...38
Ministry of Fisheries and Coastal Affairs...42
Ministry of Defence...43
Ministry of Justice, including the Office of the Governor of Svalbard...44
Ministry of Agriculture and Food ...44
Ministry of the Environment...46
Ministry of Trade and Industry...48
Ministry of Petroleum and Energy ...49
Ministry of Transport and Communications ...49
Directorate of Customs and Excise (for the Ministry of Finance)...51
Ministry of Education and Research ...52
Chapter 9: Economic and administrative consequences ...53
Chapter 9: Economic and administrative consequences ...54
References ...56
FOREWORD
The Norwegian Government’s target is to halt the loss of biodiversity by 2010. This is an ambitious target, and achieving it will require efforts by all sectors that have
impacts on biodiversity. We are therefore pleased to be able to present Norway’s first cross-sectoral strategy on invasive alien species, which will be an important element of the Government’s efforts to achieve its biodiversity target.
Alien species are a growing problem in Norway. Globally, they are considered to be one of the most serious threats to biodiversity.
The large volume of trade and travel in the modern world increases the risk that animals, plants and microorganisms will be brought along as ”hitchhikers” and be released in areas where they do not occur naturally. Most alien species do not survive in their new surroundings, but some are able to establish themselves. From hard experience, we know that some of them will cause considerable problems in both ecological and economic terms. Unfortunately, it is very difficult to predict which species will cause problems and which will be relatively harmless.
The Government has therefore based its strategy on invasive alien species on the precautionary principle. The main focus is on efforts to prevent alien species from being introduced to Norway. We will also follow a restrictive approach to granting permission for the intentional introduction of alien species.
Last but not least, we will intensify efforts to control and contain and, if appropriate, eradicate alien species that are a threat to Norwegian biodiversity or to commercial activities based on natural resources and the environment.
Norway’s policy is that each sector is responsible for the environmental impacts of its own activities. This strategy shows that the sectors are assuming their responsibility.
Helen Bjørnøy Minister of the Environment
Liv Signe Navarsete Minister of Transport and Communications
Terje Riis-Johansen Minister of Agriculture and Food
Helga Pedersen
Minister of Fisheries and Coastal Affairs
Kristin Halvorsen Minister of Finance
Odd Roger Enoksen Minister of Petroleum and Energy
Øystein Djupedal Minister of Education and Research
Dag Terje Andersen Minister of Trade and Industry
Anne Grete Strøm Eriksen
Minister of Defence Knut Storberget
Minister of Justice and the Police
CHAPTER 1: INTRODUCTION
The introduction of invasive alien species is considered to be one of the most serious threats to global biodiversity. Alien species can also have substantial economic and social impacts.
People have moved plant and animal species to new areas throughout history: often, this has been for our own benefit, to use them as agricultural crops or livestock. In many cases, the consequences of such introductions have been mainly positive or neutral.
More recently, there has been a considerable rise in introductions of alien species, particularly as a result of changes in international patterns of transport and trade. This has resulted in growing awareness of the negative impacts certain species can have when they are introduced outside their natural distribution ranges.
In Norway, too, the introduction and spread of invasive alien species is a serious and growing threat to the conservation of biodiversity and ecosystem functions, and has already inflicted heavy costs on society.
Dealing with alien species involves a complex set of challenges. Most introduced species are not able to survive and spread in the wild. Others become established without harming the ecosystems where they are introduced. But some species both become established and cause significant damage to ecosystems, for example by displacing native species or spreading disease. These are known as invasive alien species, and they can have very serious negative impacts, both on ecosystems and biodiversity and on industries such as agriculture, fisheries and aquaculture that are based on the use of these ecosystems.
Measures to address the problem of invasive alien species in Norway will also be important in efforts to achieve the target of halting the loss of biodiversity by 2010.
Under the UN Convention on Biological Diversity (CBD), Norway has undertaken as far as possible and as appropriate to prevent the introduction of, control or eradicate those alien species which threaten ecosystems, habitats or species.
Many different bodies in a range of administrative sectors are responsible for action to address the problem of alien species and for administration and enforcement of
legislation relating to the introduction, spread, and management and control of alien species. Effective action to reduce the threat from alien species therefore requires targeted and coordinated cross-sectoral efforts. The decision to draw up a cross- sectoral national strategy on alien species was taken in the 2005 white paper on the government’s environmental policy and the state of the environment in Norway (Report No. 21 (2004–2005) to the Storting) and the subsequent debate in the Storting.
This document describes Norway’s goals and principles for dealing with alien species and specific measures that will be implemented in all relevant administrative sectors.
The strategy is intended to ensure that there is a common understanding and
consistent way of dealing with problems relating to alien species, regardless of which sector is affected or is responsible for addressing the problems.
In this document, the term “alien species” is used to mean species, subspecies or lower taxons, including populations, that have been introduced outside their normal range by human activities. Species that alter their range as a result of climate change, whether natural or anthropogenic, are not considered to be alien species, and this strategy does not apply to them.
The administrative sectors involved have drawn up the programme of measures, which describes what should be done in the short term to prevent alien species from causing damage to the environment or to the health of domesticated animals and plants. The strategy focuses on new measures and does not describe activities and measures that have already been carried out and completed. It is also intended to provide a basis for coordinated development of measures and instruments in the longer term.
Once an invasive alien species has become established in the wild, it is often a very difficult and costly process to limit damage and contain the species. In marine ecosystems, which have more open boundaries than terrestrial and freshwater ecosystems, it is particularly difficult to bring species under human control in this way. The Norwegian authorities are therefore focusing their efforts mainly on preventive measures, i.e. measures to prevent new invasive alien species from being introduced into the Norwegian environment.
It is very difficult to know in advance which alien species are likely to be harmful and which will have neutral or insignificant impacts if they are introduced. This is why the precautionary principle is a key element of the authorities’ strategy on invasive alien species.
A number of ministries have cooperated in drawing up Norway’s strategy: the Ministry of Fisheries and Coastal Affairs, the Ministry of Finance, the Ministry of Defence, the Ministry of Health and Care Services, the Ministry of Justice and the Police, the Ministry of Education and Research, the Ministry of Agriculture and Food, the Ministry of Petroleum and Energy, the Ministry of the Environment, the Ministry of Trade and Industry and the Ministry of Transport and Communications. Other government agencies involved in work on alien species have also contributed: these include the Directorate for Nature Management, the Directorate of Fisheries, the Institute of Marine Research, the Norwegian National Rail Administration, the Norwegian Food Safety Authority, the Norwegian Institute of Public Health, the Norwegian Water Resources and Energy Directorate, the Norwegian Public Roads Administration, the Governor of Svalbard, the Directorate of Customs and Excise and the National Veterinary Institute. The work was coordinated by the Ministry of the Environment.
This strategy does not deal with disease control measures within the health sector, where alien species have impacts primarily on human health and not on animal health or biodiversity. Nor does it apply to genetically modified organisms (GMOs), for which Norway has established legislation and cooperation routines under the Gene Technology Act. However, there are many similarities between GMOs and alien
species, and experience of work on GMOs may be relevant in the development of legislation and in cross-sectoral cooperation and management of alien species.
Several of the species used in fish farming are domesticated variants of species that occur in the wild in Norway. It is a matter of opinion whether or not these should be classified as alien species. The Norwegian authorities consider the presence of
escaped farmed fish in the wild to be undesirable, and have implemented a number of measures to reduce this problem. These issues were discussed in Proposition No. 32 (2006–2007) to the Storting on the protection of wild Atlantic salmon (Salmo salar), and are not dealt with further in this strategy.
In May 2007, the Norwegian Biodiversity Information Centre presented a Norwegian Black List of alien species that may have negative impacts on ecosystems, indigenous species or genotypes in Norway. The first edition of the Black List is based on
ecological risk analyses of about 220 alien species that already occur in Norway. The Black List will provide a better scientific basis for setting priorities and further developing measures to combat invasive alien species in the sectors responsible for this.
The following Norwegian websites provide more information on alien species in Norway:
- Directorate for Nature Management:
http://www.dirnat.no/content.ap?thisId=2975 - Ministry of the Environment:
http://odin.dep.no/md/norsk/tema/naturmangfold/fremmede_arter/bn.html - Norwegian Biodiversity Information Centre: http://www.biodiversity.no More information on alien species can also be found on the following websites:
- Convention on Biological Diversity:
http://www.biodiv.org/programmes/cross-cutting/alien/default.shtml - North European and Baltic Network on Invasive Alien Species, NOBANIS:
http://www.nobanis.org/
CHAPTER 2: BACKGROUND
The 2005 white paper on the Government's environmental policy and the state of the environment in Norway (Report No. 21 (2004–2005) to the Storting) presents a number of measures designed to halt the loss of biodiversity by 2010. These are discussed in Chapter 2 on key priorities and in Chapter 3 on conservation and
sustainable use of biodiversity. One of the measures concerns alien species and reads as follows:
The Government will:
o Draw up a cross-sectoral national strategy for alien species by 2006
In the white paper, the Government indicates that the strategy must include the following:
o measures to prevent the spread of alien tree species through forestry activities, to prevent the spread of alien plant species along roads and other types of transport infrastructure, and to prevent the spread of alien species and populations through aquaculture activities. Implementation of the Ballast Water Convention, which Norway plans to ratify in 2005, will be important in connection with the preparation of the strategy.
In addition, the white paper states that:
In the course of 2006, the Norwegian Biodiversity Information Centre will draw up a
“black list” of alien species that may threaten or are already threatening ecosystems, habitats or other species in Norway. Efforts to survey and monitor priority alien species will be intensified. A review of the economic consequences of introductions of alien species will be initiated, among other things as a basis for cost-benefit analyses of relevant methods of eradication, containment and control. Steps will be taken to build up Information on the impacts of introductions of alien species.
The Standing Committee on Energy and the Environment considered the white paper on 2 June 2005. A majority of its members agreed that a cross-sectoral strategy should be drawn up for further work on alien species. A majority of the committee also pointed out that not all introduced species should be classified as invasive and undesirable, and pointed to the example of plant species used in agriculture and horticulture. The committee also referred to earlier debate on the red king crab (Paralithodes camtschaticus), expressed concern at its rapid spread, and referred to two proposals that were adopted in the Recommendation S. No. 192 (2004–2005) to the Storting on industrial and commercial development of marine resources. The majority of the committee also asked for measures to be taken to prevent further spread of the minnow (Phoxinus phoxinus).
CHAPTER 3: DEFINITIONS
The following definitions are used in this strategy:
Alien species – a species, subspecies or lower taxon, including a population, introduced outside its natural past or present distribution. This includes any part, gametes, seeds, eggs, or propagules of such species that might survive and subsequently reproduce.
Invasive alien species – an alien species whose introduction and/or spread may threaten native biodiversity and/or the health of domesticated plants and animals.
Species – groups of natural populations that interbreed and that are reproductively isolated from other such groups.
Introduction – the movement by human agency, direct or indirect, of an alien species outside its natural range. This movement may be either within a country or across national borders.
Intentional introduction – the deliberate movement and/or release by humans of an alien species outside its natural range.
Unintentional introduction – all other introductions that are not intentional.
Secondary introduction – a secondary introduction takes place as the result of an intentional or unintentional introduction into a new area, when the species disperses from that point of entry into areas it could not have reached without the initial (primary) human-mediated introduction.
Biodiversity – variability among living organisms from all sources, including terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are part; this includes diversity within species, between species and of ecosystems.
CHAPTER 4: THREATS, CAUSES AND IMPACTS
General background
Animals and plants have been migrating northwards into Norway ever since the ice sheets began to retreat at the end of the Ice Age about 10 000 years ago, resulting in the biodiversity we now find in the Norwegian environment. Natural barriers to dispersal such as the sea, mountains and rivers have meant that ecosystems and their plant, animal and microorganism communities have developed in different ways.
Climatic, chemical and physical conditions have also limited the geographical areas of Norway where various species have been able to become established. To some extent, species have become adapted to their habitats in Norway, although the degree of local genetic adaptation is limited in the relatively “young” ecosystems we find in Norway.
Although the Norwegian environment is young in geological terms, many fairly stable, well-established ecosystems have developed. These include both more or less undisturbed ecosystems such as virgin forest, and semi-natural ecosystems such as hay meadows and coastal heaths. A common feature of all such ecosystems is that they contain many specialised species that may disappear when environmental conditions change, for example as a result of the introduction of alien species.
Today, the rapid growth in the volumes of goods and passenger transport and the elimination of border controls between countries and continents are resulting in dramatic change, and many species are being spread to new areas where they do not occur naturally. Alien species are introduced from all parts of the world, whether deliberately as commodities or as stowaways on people, animals, plants, goods and vehicles. In the long term, much of the variety in nature and a great deal of
biodiversity may be lost.
The consequences of the current trends are largely unknown. It is difficult to predict whether or not an organism that is introduced to a new area will become a problem.
Most alien species in Norway die out rapidly because they are not adapted to the local ecosystems. However, in some cases there are no natural enemies to regulate the populations of new species, or other characteristics allow them to survive in a new environment. Moreover, it may take many years before an introduced organism shows signs of being invasive. For example, the sycamore (Acer pseudoplatanus) was
introduced to Norway as an ornamental tree about 250 years ago, but it has only begun to spread widely and become invasive in the last 30–40 years. The sycamore is now considered to be a problem in several protected areas that were established to maintain Norwegian deciduous broad-leaved forests.
At global level, the spread of alien species is one of the most serious threats to biodiversity1. Norway is one of 190 parties to the UN Convention on Biological
1 For example, the UN Millennium Ecosystem Assessment states, “The most
important direct drivers of change in ecosystems are habitat change (land use change and physical modification of rivers or water withdrawal from rivers),
overexploitation, invasive alien species, pollution, and climate change”.
(http://www.maweb.org/documents/document.356.aspx.pdf)
Diversity (CBD), and has thus undertaken as far as possible and as appropriate to
“prevent the introduction of, control or eradicate those alien species which threaten ecosystems, habitats or species.”
Even though many alien species do not have negative impacts, the examples we have seen of problems caused by invasive species show that it is essential to have good routines for evaluating whether the introduction of an organism to a new area should be permitted. Carrying out an environmental risk assessment before the intentional introduction of an alien organism is difficult, but it must be done. The ecological interactions between alien and native species are complex, and there are still many gaps in our knowledge. The intentional introduction and release of alien species must therefore only be permitted after thorough evaluations based on the precautionary principle. One example of routines for such evaluations is set out in the 2004 ICES Code of Practice on the Introductions and Transfers of Marine Organisms. Alien species that may be invasive in the Norwegian environment include species that are intentionally or unintentionally introduced into the country and also those that occur naturally in Norway but that are spread to new areas through human activity.
The boundaries between marine ecosystems are less clear-cut than those between terrestrial and freshwater ecosystems, so that the marine environment is more continuous. This means that organisms spread more readily between and through different areas of sea, particularly those that are pelagic for part or all of their life cycles. Factors that govern water transport therefore have a strong influence on the transport and dispersal of organisms in the marine environment. Nevertheless, there is wide variation in ecosystems and in the species found in different sea areas, and this is true within Norwegian waters as well. Factors such as salinity, temperature, currents, wave exposure and bottom types are important in determining which species are found in an area, and also in determining which new species will be able to establish themselves in an ecosystem.
Numbers of alien species registered in freshwater, marine and terrestrial ecosystems in the Nordic countries (Norway, Sweden, Denmark, Finland and Iceland). Source: NOBANIS. According to the most recent overview from the Norwegian Biodiversity Information Centre (May 2007), almost 2500 alien species have been registered in Norway.
Alien species have spread to many protected areas; the most
conspicuous examples in Norway today are the sycamore and the Japanese rose (Rosa rugosa). Both of these are able to outcompete native species, and are therefore in many cases considered to be a threat to the habitats that the conservation
measures are intended to protect.
Alien tree species are a threat to many protected areas, and have been particularly widely planted in
Western and North Norway. Several of these species can set viable seed in Norway, and some have spread extensively from the sites where they were originally planted. In the long term, more protected areas will come under threat unless control measures
are implemented both within and outside protected areas.
European tree frog (Hyla arborea)
This frog was found in the fruit aisles of a supermarket in Trondheim in April 2007. The species is not native to Norway, and probably arrived with a consignment of fruit from Spain. Live animals and plants that enter the country as hitchhikers on imported goods are a serious problem.
Photo: Heidi Hansen
Species that have previously been introduced to Norway without being able to
establish significant populations or spread to any great extent may become invasive in future as a result of global anthropogenic climate change.
Social and economic impacts
Invasive alien species are not only a threat to natural ecosystems and wild plants and animals; they have also had serious impacts on human health and the health of domesticated plants and animals. It is a constant challenge to deal with the introduction of disease-causing organisms that are imported with animals, plants, goods and transport equipment. There are several examples of alien species that are causing damage in Norway (more examples can be found in the sections on problems within individual sectors).
- The salmon parasite Gyrodactylus salaris came to Norway with imported salmon smolt and rainbow trout (Oncorhynchus mykiss) fingerlings from Sweden in 1975. Gyrodactylus now causes annual losses in the order of NOK 200–250 million in Norwegian river systems.
- The alga Chattonella cf. verruculosa caused serious losses in the fish farming industry along the coast of Southern Norway in 2001. Almost 1000 tonnes of farmed fish worth NOK 25 million died. The alga was first registered in Norway in 1998, and may have reached Europe from the Far East with ballast water.
- Efforts to eradicate the South American leafminer Liriomyza huidobrensis cost the horticulture industry NOK 40–50 million in 2002. The species reached Norway as a stowaway on imported plants.
- In the period 1969–74, the opossum shrimp Mysis relicta was released as a food species for trout in nine regulated lakes in Central Norway in order to mitigate the adverse impacts of hydropower developments. In one lake, Selbusjøen, this had an unintended negative impact: the Arctic char
(Salvelinus alpinus) population dropped as a result of competition between Mysis and char. The Norwegian Supreme Court granted the landowners NOK 5 million in damages.
- Bioforsk, the Norwegian Institute for Agricultural and Environmental Research, was commissioned by the Directorate for Nature Management to investigate the costs of the unintentional introduction of potato blight Phytophthora infestans and the western flower thrips Frankliniella occidentalis. Bioforsk concluded that the annual costs of potato blight,
including crop yield losses and the costs of eradication and advisory measures, amount to NOK 55–5 million. For the western flower thrips, the annual costs are between NOK 436 and 582 million, given yield losses of 30–0%.
Globally, the costs of dealing with alien species are high in various sectors, including agriculture, forestry, fisheries and health care. Cornell University has calculated that in the US alone, the overall costs are an estimated USD 123 billion a year. Control costs are highest for crop weeds and animal pests in the agricultural and forestry sectors.
Minnow (Phoxinus phoxinus)
For many years, human activity has helped to spread the minnow to new areas of Norway, and it is probably becoming the most widely distributed freshwater fish in the country. The minnow is a small fish belonging to the carp family: it can reach a length of up to 15 cm, but does not usually grow much beyond 8–10 cm. Its natural distribution in Norway was largely limited to lower-lying areas in southeastern Norway and some of the larger rivers in Finnmark county in the far north. It has now been spread to every county in Norway (see map), mainly as a result of deliberate and accidental releases and the use of live bait.
Minnows are very adaptable and can establish dense populations that displace native fish stocks. Trout stocks in many lakes have declined greatly after the introduction of minnows. Thus, the spread of minnows is a threat not only to biodiversity, but also to the value of Norway’s river systems for angling and outdoor recreation. The introduction of minnows to the Hardangervidda mountain plateau has resulted in competition for food between birds and fish and displaced red-listed diving ducks such as velvet scoter (Melanitta fusca) and scaup (Aythya marila).
Minnows are now spreading to the Namsen river in Nord-Trøndelag, where they may be a serious threat to the critically endangered dwarf stock of Atlantic salmon in the river, which is unusual in spending its whole life cycle in fresh water.
In 1999 and 2000, rotenone treatment was carried out to eradicate minnows from the Hardangervidda and prevent their spread to rivers in the central part of the plateau. The treatment cost about NOK 4 million, and has so far been successful. In 2005, NOK 2 million was allocated to measures to prevent the spread of minnows and certain other freshwater organisms. This has been used to map the occurrence of minnows in the Namsen river system. Some of the tributaries of the Namsen were treated with rotenone to prevent minnows from become established in the main river. Funding was also provided for information activities to prevent the spread of minnows and for trap fishing to
Agriculture
The introduction of alien species can have serious impacts in the agricultural, forestry and horticultural sectors as regards plant health, animal health and food security.
Invasive alien species that are intentionally or unintentionally introduced in connection with these activities can also constitute a threat to biodiversity.
Forestry
There are two main issues to be considered relating to alien species and the forestry industry. One is the use of alien tree species in forestry, and the other is problems that can arise in connection with imports of timber and wood products.
About 50 introduced tree species have been used in Norwegian forestry. About 10 of these have been planted more widely than in purely experimental plots. Alien species have been particularly widely used in afforestation in Western and North Norway.
The total area that has been afforested in Western Norway is about 160 000 hectares, which is equivalent to 18% of all productive forest in the region. The corresponding figures for Nordland and Troms counties in North Norway are 0.9 million hectares and about 10% of all productive forest in these counties. Most of the total area afforested and also areas replanted
with different tree species have been planted with Norway spruce (Picea abies), which does not occur
naturally in Western Norway or most of North Norway.
Sycamore (Acer pseudoplatanus)
The sycamore is native to hilly and mountainous areas of central and southern Europe. It was introduced to Norway as an ornamental tree, probably around 1750. It has gradually become established in various forest habitats, and has become the dominant broad-leaved tree in certain areas. It can also be found in spruce forest. It is now spreading very rapidly, and observations from the coast and fjords of Western Norway show that it is competing strongly with native deciduous broad-leaved trees. Photo:
Hilde Friis Solås
In 2005, about 3.5% of all trees planted were of alien species, and about 75% of these were planted for the production of Christmas trees and ornamental greenery. This means that alien species accounted for 0.9%
of the trees planted in forested areas, or about 15 000 plants. This is somewhat lower than the average for recent years. There is no prohibition against using alien tree species, but the new Forestry Act and regulations on sustainable forestry will be used to regulate the use of introduced tree species. In recent years, the National Forest Inventory, a national
monitoring programme, has been expanded to include alien tree species and their spread, and various projects have been carried out to gather information on alien tree species in Norway. Research in this field and analyses of the effects of
introduction of alien species and genotypes are being funded through the research programme Biological Diversity (1998–2007). Norwegian forestry policy is no longer focusing on further afforestation and replanting of different tree species using alien species.
However, there are problems related to the alien tree species that have already been planted. The Ministry of Agriculture and Food has funded a project run by the Norwegian Forest and Landscape Institute to study the natural spread of alien tree species. Certain species have proved to have the high dispersal ability in the Norwegian environment. They may have major ecological effects on a local scale.
More than 2 million m3 of timber is imported to Norway every year. Most of it comes from the Baltic states and the European part of Russia, where ecosystems are similar to those in Norway and there are few pest species that are not also found in Norway.
Nevertheless, there is a risk that alien species will be imported with timber. Since 1999, field studies have been carried out in Russia, and ports where timber is imported to Norway have been monitored. Many species have been found on imported timber. Most of these occur in Norway, but some new species have been registered. The dispersal ability of such species and the effects they may have on Norwegian ecosystems are being assessed on a continuous basis.
Wood that is not sufficiently dried or completely debarked can be a pathway for the introduction of pest species. A number of countries require documentation that the moisture content of imported wood does not exceed 20%; alternatively, the wood can be debarked. These requirements have been introduced because pests can survive in the bark if the moisture content is too high. Many countries have also introduced phytosanitary regulations for the import of wooden pallets and other packaging materials of wood for imported goods.
Agriculture and horticulture
South American Leafminer (Liriomyza huidobrensis)
Since 1995, there have been a number of finds of South American leafminers in Norwegian greenhouses. So far, the species has been successfully eradicated by a concerted effort in each greenhouse where it has been found. Leafminers puncture leaves to lay their eggs, and the larvae tunnel through the leaves, creating irregular
“mines”. Damage to the leaves reduces crop yields and reduces the value of ornamental plants. In 2002, eradication measures cost the horticulture industry NOK 40–50 million. The species reaches Norway as a hitch- hiker on imported plants. Photo: Bioforsk
Growing international trade, travel and other activities are putting increasing pressure on plant health.
To maintain good plant health in Norway, the authorities are therefore giving high priority to preventing the introduction and spread of plant pests and to combating or
eradicating any outbreaks of such pests in the country.
Many different species are imported, produced and sold as plants,
including seeds and other plant propagating material, and may be used for agriculture or horticulture (open-air production or in
greenhouses), or in parks, private gardens and so on.
The Ministry of Agriculture and Food regulates trade in plants through phytosanitary regulations pursuant to the Food Act. The main purpose of this legislation is to protect plant health, and the risk of the spread of invasive alien species that are not an indirect or direct threat to plant health is therefore not specifically regulated. However,
ensuring high phytosanitary standards for cultivated plants also reduces the likelihood that pests will spread to wild plants.
The Norwegian Food Safety Authority is the supervisory authority for plants, parts of plants and other regulated articles that may carry pests that are imported to or
produced or sold in Norway. For imports, checks are carried out to ensure that consignments for which this is mandatory2 are accompanied by satisfactory phytosanitary certificates documenting compliance with Norwegian import
requirements. In addition, spot checks of such consignments are made to inspect them for quarantine pests. The Food Safety Authority may also decide to inspect
consignments for which phytosanitary certificates are not required.
Norway’s Regulations relating to plants and measures against pests prohibit the import of certain plants, parts of plants, organisms and plant pests, and soil from certain areas. The Norwegian Food Safety Authority may nevertheless on application and on certain conditions permit the import of such articles for research or cultivation purposes. The Authority bases its pest risk management on pest risk assessments carried out by the Norwegian Scientific Committee for Food Safety.
Spanish Slug (Arion lusitanicus)
The Spanish slug was first found in Norway in 1988. It occurs naturally in southern Europe, mainly on the Iberian peninsula and in southern France. It is relatively rare in this area, probably because of the hot and dry conditions combined with the presence of natural enemies. The species has spread rapidly since it was first introduced to Norway. It thrives in the damp, cool Nordic climate, and is found mainly in cultural habitats. Slugs are spread with soil, compost and plant material. The reproductive potential of this species is higher than that of the native black slug (Arion ater), which has been shown to decline in areas where there are large numbers of Spanish slugs. This may be both because of interspecific competition and because Spanish slugs eat black slugs. Photo:
Lisbeth Gederaas
2 Details are set out in Annex 5 of the Regulations relating to plants and measures against pests
The Norwegian Scientific Committee for Food Safety carries out independent risk assessments for the Food Safety Authority, and environmental risk assessments of genetically modified organisms for the Directorate for Nature Management. The Food Safety Authority uses these risk assessments as a basis for its activities and priorities and for input to the ministries on determining an appropriate level of protection. They are also used as a basis for deciding which measures to implement, for example in drawing up new regulations and instructions and when new information on risks becomes available. The Scientific Committee thus plays an important role in the Food Safety Authority’s work relating to safe and wholesome food, cosmetics, animal health, animal welfare, plant health and relevant environmental considerations.
The Scientific Committee for Food Safety is an independent organisation with its own secretariat. In addition to providing assessments as requested by the Food Safety Authority, the Committee considers other matters on its own initiative to ensure that important issues are evaluated
independently of the priorities of the public administration and politicians.
Japweed (Sargassum muticum)
Japweed (Sargassum muticum) originally reached Europe (France) attached to the shells of live imported Pacific oysters (Crassostrea gigas). It rapidly established populations in the wild, and spread to the southern part of the Norwegian coast with the coastal current. It is now found from the Oslofjord to north of the Sognefjord, and forms dense stands in sheltered localities. It grows fast, particularly in warm summers, and can reach a length of several metres, becoming a nuisance for small leisure craft in harbours. The photograph shows Japweed on the right, and three of the species it can compete with: in the centre, toothed wrack (Fucus serratus, appearing dark green), further left, bladder wrack (Fucus vesiculosus, lighter green), and on the far left, knotted wrack (Ascophyllum nodosum) Photo: Jan Rueness.
Any firm that imports, produces or sells plants, including seeds and other plant propagating material, to another stage in the chain of
distribution or for commercial cultivation is required to register with the Food Safety Authority. The Food Safety Authority carries out inspection and control of registered firms to prevent the introduction and spread of the serious plant pests listed in the regulations with imported or Norwegian-produced plants. There is no approval scheme for plant species for import or for production and sale, but the import and cultivation of seeds of narcotic plants is prohibited, and Annexes 3 and 7 of the regulations list species that it is prohibited to import or plant and sell.
Fisheries, aquaculture and imports and other movements of live aquatic organisms
In the marine environment, there are special challenges relating to alien species because boundaries between sea areas are not clear cut, our knowledge of species diversity is inadequate, and it is generally difficult to register new species before they become established in ecosystems, and more difficult than in other environments to eradicate alien species that have become established.
Under Norwegian fisheries legislation, it is prohibited to release organisms and live eggs into fjords or the sea without permission from the Ministry of Fisheries and Coastal Affairs. Permission may be granted in the form of regulations for particular species and specified areas, or in the form of individual decisions.
Alien species have played a major role in the development of the fish farming
industry in Europe. Important alien species include the rainbow trout and the common carp (Cyprinus carpio). However, the use of alien species in aquaculture has been one of the most important pathways for the introduction of alien species to Norwegian and European waters. Restrictions that have already been introduced have reduced this problem considerably.
Norway now has a general prohibition against the use of alien species in aquaculture, both in fish farms and for sea ranching. There are risks associated with the use of alien aquaculture species, both because they can spread to the wild and because they may carry diseases and parasites. However, the level of risk will depend on how isolated the animals are from the natural environment. Sea ranching involves releasing animals to the natural environment, and using alien species for this would involve intentional introductions, which as a general rule are strictly forbidden. Exceptions can nevertheless be made for the use of alien species in aquaculture if a risk
assessment indicates that this will not have an adverse impact on natural ecosystems.
Imports of live aquatic organisms have resulted in the introduction of serious diseases that can threaten the existence of wild populations. As mentioned earlier, the salmon parasite Gyrodactylus salaris was introduced to Norway in the 1970s and 1980s, when large numbers of salmon smolt and some rainbow trout fingerlings were imported from Sweden and Finland. So far, 46 rivers have been infected with Gyrodactylus. The environmental, fisheries and veterinary authorities are cooperating on a concerted effort to prevent further spread of the parasite and to eradicate it from river systems that have been infected.
Imports of alien aquatic species to new countries and regions for human consumption can also result in their introduction in the wild. For
example, live American lobsters are imported to Norway for sale at fish
markets and in fishmongers. In recent years, they have been illegally released at several localities in the southern part of Norway, and may become a serious problem
American Lobster (Homarus americanus)
The American lobster differs from the European lobster (H.
gammarus) in its greenish-brown colouring and in generally having one or more spines on the underside of the rostrum. However, some European lobsters show similar colouring, and DNA analysis is therefore necessary for definite identification. The American lobster has been shown to carry lethal lobster diseases and parasites that do not occur naturally in the European lobster. Since 1999, American lobsters have been caught a number of times in Norwegian waters, some of them with fertilised roe. The illegal release of live lobsters imported for consumption is believed to be the main source of American lobsters in Norwegian waters.
Photo: Institute of Marine Research
for the Norwegian lobster stock and for other species in coastal waters. The American lobster is adapted to cold water and can travel several hundred kilometres in the course of a year. Control and information measures are being implemented to prevent further releases of the species.
In the 1960s, Russian scientists intentionally released red king crabs in the Murmansk fjord to provide a new commercial resource for the local population. Since then, the species has spread both eastwards and westwards in the southern part of the Barents Sea, and is probably permanently established. So far, we know little about what negative impacts it may have on the original fauna. In both Russian and Norwegian parts of the southern Barents Sea, observations show that the largest individuals of certain species (starfish, molluscs and echiurans) disappear from areas where king crabs have been present for a long time. This gives small, rapidly growing species more chance of surviving and breeding, thus altering the structure of the benthic community. In addition, space becomes available for other, more opportunistic species.
The red king crab is a valuable resource, but there is now growing concern about the fact that it is an alien species.
Extensive research on its ecological impacts has been started, and a white paper is being drawn up on
management of the species in Norwegian waters.
Freshwater ecosystems
Norwegian freshwater ecosystems typically contain few species. In Western Norway, there are generally only two to four fish species in rivers and lakes. It is important to protect such rare species-poor ecosystems.
Measures must therefore be taken to prevent the further spread of alien freshwater species in these
ecosystems and to eradicate alien species that have already become established. This is particularly important with respect to species that have the potential for further
dispersal. The spread of minnows and other members of the carp family such as the common carp, goldfish (Carassius auratus), roach (Rutilus rutilus), belica (Leucaspius delineatus), tench (Tinca tinca) and rudd (Scardinius erythrophthalmus) is a particularly serious problem.
Some other species such as pike,
perch and lake trout (Salvelinus namaycush) are also spreading rapidly.
Signal Crayfish
(Pacifastacus leniusculus)
The signal crayfish is an American freshwater crayfish that was introduced to Sweden in 1960. It carries the crayfish plague, a serious fungal disease that has little effect on the signal crayfish but kills the European species, the noble crayfish (Astacus astacus). The noble crayfish is listed as endangered in the 2006 Norwegian Red List. The greatest threat to the noble crayfish is the spread of crayfish plague to new rivers with signal crayfish or on fishing gear or boats contaminated with the fungus. Crayfish plague is causing serious problems in two Norwegian river systems, Glomma and Haldenvassdraget. In October 2006, signal crayfish were found in a series of small lakes in a protected landscape near Porsgrunn (Telemark county), and studies showed that the crayfish plague is also present here.
The signal crayfish was introduced to Sweden from the US in 1960. It carries crayfish plague, a disease that has little effect on the signal crayfish but kills the European noble crayfish. Both the signal crayfish and crayfish plague have spread to Norway, and are considered to be the most serious threat to the endangered noble crayfish.
Photo: Jarle Steinkjer
There is also a risk of the introduction of alien aquatic species in connection with imports of live fish for aquaria and ornamental ponds. A North American fish, the pumpkinseed (Lepomis gibbosus), was found in some small lakes in Asker west of Oslo in 2005. The species may have been introduced by aquarists or anglers. There are currently no restrictions on imports of fish that are only to be kept in closed aquaria.
Shipping, including ballast water
About 45 alien species are currently established in Norwegian waters. Important pathways of introduction are via hull fouling and ballast water. The risk of
introductions rises with the volume of shipping, particularly with transport from areas with a similar marine climate. A warmer climate may increase the likelihood that species introduced from further south will be able to establish themselves in Norwegian waters, and if the Northern Sea Route is opened for traffic, this may increase the risk of introductions from distant areas with a similar marine climate.
Norwegian waters cover some of the most productive marine areas in the world, and Norway has the longest coastline in Europe. The coastal zone is a valuable natural environment in its own right, as well as providing valuable resources and a basis for commercial marine activities. Invasive alien species can have a major impact in both ecological and economic terms.
Ships have to carry ballast water to provide balance and stability, and as a result water is transported from one port to another. At any time, more than 7000 species are in transit in ballast water tanks in ships worldwide. The combination of a large volume of shipping and locally large discharges of ballast water containing alien species means that Norwegian waters are at relatively high risk.
The International Maritime Organization (IMO) adopted the International Convention for the Control and Management of Ships’ Ballast Water and Sediments on 13
February 2004. The Convention will enter into force one year after at least 30 states that together account for 35% of world merchant shipping tonnage have ratified it.
Norway was one of the first countries to ratify the Convention, on 29 March 2007.
Ships’ hulls and other surfaces are another pathway for the introduction of alien species, but one that has so far received less attention than ballast water.
New climate – new species
With rising temperatures, it is expected that more southerly species will extend their range to Norway, and others will spread northwards through Norway or perhaps to other countries, without human intervention. Species whose distribution ranges alter as a result of natural or anthropogenic climate change are not considered to be alien species, and this strategy does not apply to them. Nevertheless, it may be necessary for example to monitor certain species that prove to pose a particular threat to commercial activities or environmental assets, and drawn up contingency plans to deal with them. Climate change will also make it more difficult to distinguish between introduced and naturally occurring species.
Hydropower developments and management of river systems A number of hydropower developments have created new connections within and between river systems, and this in turn has resulted in the dispersal of aquatic organisms. It is difficult to guard against such introductions, for example if fish and small pelagic crustaceans are carried by flowing water. For example, a water transfer scheme (part of a hydropower development) in Nord-Trøndelag resulted in the spread of the opossum shrimp between lakes, and in Hordaland, Arctic char have been transferred from one river system to another as a result of the construction of a pumped storage power plant.
Preventing the spread of alien species is one issue that must be considered when dealing with licence applications for hydropower developments under Norwegian legislation, and has received increasing attention recently. In cases where there is a risk of the spread of invasive alien species, the authorities consider whether to issue orders for preventive measures or refuse the application.
Developers are often required to restock rivers after hydropower developments to compensate for lost fish production.
Such measures may have resulted in the spread of unwanted species: for
example, there are strong indications that they played a role in the spread of minnows in the 1970s. Previously, fish used to stock rivers came from central facilities, and the fish were not from local populations. The whole stock enhancement system in Norway has now been completely reviewed with a view to conservation of local genetic resources.
Fish that are used to stock rivers today are from local stocks.
The salmon parasite Gyrodactylus salaris
The salmon parasite Gyrodactylus salaris is barely visible to the naked eye. It lives on the skin and fins of juvenile salmon, and is considered to be the most serious threat to wild salmon stocks in Norway. Of the 46 Norwegian salmon stocks that have been infected with the parasite, 10 have already become extinct and another 20 are at risk of extinction. The only long-term measure that has proved to be effective against the parasite is its permanent eradication. Fifteen rivers have been chemically treated and are considered to be free of the parasite.
The annual losses caused by Gyrodactylus in Norwegian rivers are in the order of NOK 200–250 million, and consist mainly of lost income from salmon fishing in infected rivers, lost income from salmon fishing in neighbouring fjords, and loss of the substantial economic spin-off benefits from salmon fishing. A rough estimate suggests that Norway’s losses since the introduction of Gyrodactylus salaris 30 years ago are in the order of NOK 3–4 billion.
It has been estimated that eradicating Gyrodactylus salaris from all Norwegian river systems indicates will take 12–18 years at a total cost of NOK 340–400 million.
Photo: Tor Atle Mo
Regulation of watercourses can result in changes in the species balance and in living conditions in the river, and this in turn may influence how readily
organisms that are introduced into the river become established there.
Licensees are responsible for revegetation of spoil heaps, tracks, ditches and so on, and alien species are sometimes used for this purpose. The Norwegian Water Resources and Energy Directorate has issued guidelines for revegetation, and recommends allowing vegetation to establish itself naturally or planting/sowing site-specific plant species.
Many plant species, a number of which were originally introduced as garden plants, are now becoming established in the wild along Norwegian rivers. Some examples are the two introduced hogweeds, Himalayan balsam (Impatiens glandulifera), Japanese knotweed (Fallopia japonica) and common butterbur (Petasites hybridus). These species displace plants that grow naturally along rivers and streams, stabilising the soil and preventing erosion. In contrast to many native plant species, a number of alien species die right back in autumn, leaving open soil. Open soil at times of year when rainfall is high increases erosion, and may result in sediment deposition that smothers fish spawning sites and prey animals.
Transport
The transport sector may contribute to the spread of alien species in the following ways:
• By planting and sowing alien species
• By leaving soil fallow, making it easier for new species to become established
• By mowing verges
• Through earthmoving operations and movement of machinery during construction activities
• By constructing new links (bridges and tunnels) that give access to new species, including predators.
Railways and roads are important pathways of introduction for plants. Many of these cause no problems, but some tend to spread to other habitats where they may displace the natural vegetation. Examples of invasive species found along roads and railways are the two introduced hogweed species, lupins, Canada goldenrod (Solidago
canadensis)and Japanese knotweed.
Earthmoving, planting and maintenance of green spaces can result in the spread of invasive alien species. In addition, linking islands to the mainland or building roads to other isolated areas can facilitate the spread of species that were not previously found there, and thus change ecological conditions. Species may also be unintentionally spread between river systems when signs and road equipment are washed using water from mobile tanks.
Construction
During the construction of roads, railways and other infrastructure, earthmoving operations may result in the spread of biological material and thus of alien species, damaging natural ecosystems. Excavation, for example of drainage ditches, and other physical disturbance can also make it easier for unwanted species to become
established.
Invasion pathways
Links between islands and the mainland can provide access for new animal and plant species. Islands and other areas that have previously been inaccessible to certain species have a species composition that is adapted to this situation. For example, islands without mammalian predators are attractive nesting sites for birds.
Roads can also function as pathways for the introduction of plants. Seeds and other parts of plants may be spread by vehicles, when verges are mown, or during road sweeping or transport of earth or snow.
The presence of open areas with little vegetation is probably the main reason why plants readily spread along railways. Open soil is a suitable habitat for the
establishment of alien species. The wind created by passing trains can also help to spread seeds from plants and from the soil. Seeds can also become attached to rolling stock and be transported for longer distances, even across national borders.
A causeway was built to the island of Tautra in Nord-Trøndelag in the 1970s, allowing foxes, badgers and pine martens to reach the island. This is the best-known example in Norway of a road functioning as a pathway for the introduction of species. The predators greatly reduced populations of several bird species on Tautra, which is both a bird reserve and a designated Ramsar site. In 2004, part of the causeway was replaced by a bridge with an electronic gate to prevent predatory mammals from crossing. The lower photo shows the opening of an improved version of the gate in April 2006. The cost of the bridge and gate was about NOK 40 million. Photos:
Per Gustav Thingstad
Vegetation
The vegetation on road verges is often a pioneer community, where there a larger numbers of invasive species than elsewhere. Annual mowing of verges limits growth and thus the spread of alien species, but encourages dispersal in other ways, for example by spreading seed.
Dispersal between river systems
Water is used on unmetalled roads and to wash signs and other road equipment. It is pumped into mobile tanks from lakes and rivers and may be used for various purposes along the roads. In this way, water taken from an infected river can end up in a
different river. This can spread organisms such as Gyrodactylus salaris, crayfish plague and Canadian pondweed from one river system to another.
The defence sector
Annual exercises are held in Norway involving foreign troops, and in this connection both materiel (including vehicles) and personnel cross the border. This could result in dispersal of alien species, although so far no cases where undesirable species have spread across the border have been linked to military activity in Norway. In addition, Norwegian personnel operating abroad could unintentionally introduce species from Norwegian ecosystems to other countries or bring alien species with them when they return to Norway. Imports of materiel also entail a risk of the introduction of alien species to Norway. These risks apply to all branches of the Armed Forces. However, the Norwegian Defence has issued instructions for movements of military materiel and personnel into and out of Norway, and these are presumed to reduce the likelihood of spreading alien species across national borders to a minimum.
Activities of the Armed Forces and movements of materiel can also spread species within the country. For example, the salmon parasite Gyrodactylus salaris can be spread by contact with water from infected rivers and lakes. Where information on such threats is available, relevant restrictions are as far as possible indicated on maps for exercises and in instructions for how areas may be used.
In cases where activities of the Armed Forces cause environmental damage,
restoration measures may be appropriate. Earthmoving and the use of seed mixtures and plant material in revegetation entail a risk of the spread of alien species.
There is a risk of the spread of alien species via ballast water from certain types of military vessels. Some military bases have treatment facilities for substances such as oil products and heavy metals. However, it has not been adequately assessed whether the existing systems are also satisfactory for the destruction of alien species. This is particularly important in connection with international exercises. At present Norway does not have good routines and effective systems for treatment of ballast water from military vessels during such exercises.
Travel and tourism
Travel and tourism is the world’s third largest industry, and one of the fastest growing. It is also the third largest industry in Norway. Travel can be divided into tourism (leisure and recreational travel), business and official travel, and travel to courses and conferences. Travel and tourism is a generic term for businesses in which sales to travellers make up a large share of production.
Nature itself has been identified as one of the most important selling points for the travel and tourism industry in Norway (2005 Action Plan for the Travel and Tourism Industry). Since nature is such an important element of the Norwegian tourism product, it is crucially important to adapt activities to the natural and cultural
environment. Knowledge of sustainable use is needed as a basis for conservation and development of the resources on which the industry is based.
Globally, travel and tourism is considered to be an important factor in the spread of alien
species. This is presumably true of travel and tourism in Norway as well. We know of several alien species that may have been
brought to Norway by tourists. For example, two freshwater fish species – gudgeon (Gobio gobio) in the river Numedalslågen and belica in Aust-Agder county – were probably introduced by foreign anglers for use as live bait.
Both species are farmed and sold commercially as bait in central Europe. The use of live fish as bait is prohibited by the Prevention of
Cruelty to Animals Act in Norway, but is permitted in neighbouring countries and many other countries in Europe.
Information – an important tool
Information is an important tool in efforts to prevent the introduction of invasive alien species. Here, a German tourist is reading information about the salmon parasite Gyrodactylus salaris and the precautions that are needed to prevent it from being spread with fishing gear, water containers, and so on.
Photo: Gry Ingebrigsten/Stabbursnes Nature House and Museum.
Travel and tourism can also result in the further spread of already established alien species in Norway. The salmon parasite Gyrodactylus salaris and crayfish plague can be spread between rivers with damp fishing gear (including clothing, footwear, boats, water containers, and so on). This is why equipment that has been used in an infected river must be disinfected before use in another river.
Under the Convention on Biological Diversity, Norway has also undertaken to provide information on alien species that cause damage in the Norwegian
environment, and that tourists should not bring into the country. Examples of such species are crayfish plague, lupins and Japanese rose. In Svalbard, the Arctic fox (Alopex lagopus) carries rabies, and both Arctic foxes and the vole Microtus rossiaemeridionalis carry the tapeworm Echinococcus multilocularis, which can cause fatal disease in people. Tourists who will be spending time ashore in the archipelago are informed of this.
Health
In some cases, invasive alien species can be a direct threat to human health as well as to biodiversity. For example, the two alien hogweed species displace other species and are thus a threat to biodiversity, but also cause serious skin burns and are thus a threat to human health. Alien species such as parasites and bacteria that are spread with people (for instance by intercontinental travel) are not generally a threat to biodiversity. However, alien species that are a health hazard and species that are harmful to biodiversity may follow the same invasion pathways. The spread of organisms with discharges of untreated ballast water from ships is a particularly relevant example. Even though disease control and the purely health-related impacts of invasive alien species are not included in the scope of this strategy, there are areas of overlapping responsibility where cooperation between the health sector and other
sectors on measures to prevent the introduction and spread of invasive alien species should be encouraged and further developed.
Svalbard
The environment in Svalbard is particularly vulnerable. A typical characteristic of ecosystems in Svalbard and other areas in the High Arctic is that they are species- poor, but that many of the species occur in very large numbers. Such ecosystems are especially vulnerable to alien species, which may change them dramatically. Several species have been introduced intentionally, for example the muskox (Ovibos
moschatus), mountain hare (Lepus timidus), the mainland subspecies of reindeer (Rangifer tarandus tarandus) and trout (Salmo trutta). In addition, species such as the vole Microtus rossiaemeridionalis have been introduced unintentionally. This vole species does not occur in mainland Norway, and it carries the tapeworm
Echinococcus multilocularis, which can cause fatal disease in humans.
All researchers and anglers in Svalbard are required to disinfect any equipment that could represent a risk of the introduction of alien species. Fishing licences set out this requirement clearly, and the authorities will impose sanctions in cases of non-
compliance. All sampling equipment must also be disinfected before use at new localities in Svalbard.
If rising temperatures and ice-melt open up new transport routes between Europe and Asia, the risk that marine species will be spread between sea areas in the north may rise. Ecosystems around Svalbard may also be affected by alien species that spread northwards after they are introduced into waters further south. Moreover, there is a certain risk that alien species will be introduced to Svalbard via ballast water carried by cargo and cruise ships. The volume of shipping calling at Svalbard is growing, and this trend is expected to continue.
Species could also be introduced from Svalbard to the mainland, and it is particularly important to maintain a focus on the rabies virus, which is present in Svalbard but not in mainland Norway.